btrfs: format checksums according to type for printing

Add a small helper for btrfs_print_data_csum_error() which formats the
checksum according to it's type for pretty printing.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ shorten macro name ]
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/btrfs_inode.h

@@ -337,22 +337,34 @@ static inline void btrfs_inode_resume_unlocked_dio(struct btrfs_inode *inode)
 	clear_bit(BTRFS_INODE_READDIO_NEED_LOCK, &inode->runtime_flags);
 }
 
+/* Array of bytes with variable length, hexadecimal format 0x1234 */
+#define CSUM_FMT				"0x%*phN"
+#define CSUM_FMT_VALUE(size, bytes)		size, bytes
+
 static inline void btrfs_print_data_csum_error(struct btrfs_inode *inode,
 		u64 logical_start, u32 csum, u32 csum_expected, int mirror_num)
 {
 	struct btrfs_root *root = inode->root;
+	struct btrfs_super_block *sb = root->fs_info->super_copy;
+	const u16 csum_size = btrfs_super_csum_size(sb);
 
 	/* Output minus objectid, which is more meaningful */
 	if (root->root_key.objectid >= BTRFS_LAST_FREE_OBJECTID)
 		btrfs_warn_rl(root->fs_info,
-	"csum failed root %lld ino %lld off %llu csum 0x%08x expected csum 0x%08x mirror %d",
+"csum failed root %lld ino %lld off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
 			root->root_key.objectid, btrfs_ino(inode),
-			logical_start, csum, csum_expected, mirror_num);
+			logical_start,
+			CSUM_FMT_VALUE(csum_size, &csum),
+			CSUM_FMT_VALUE(csum_size, &csum_expected),
+			mirror_num);
 	else
 		btrfs_warn_rl(root->fs_info,
-	"csum failed root %llu ino %llu off %llu csum 0x%08x expected csum 0x%08x mirror %d",
+"csum failed root %llu ino %llu off %llu csum " CSUM_FMT " expected csum " CSUM_FMT " mirror %d",
 			root->root_key.objectid, btrfs_ino(inode),
-			logical_start, csum, csum_expected, mirror_num);
+			logical_start,
+			CSUM_FMT_VALUE(csum_size, &csum),
+			CSUM_FMT_VALUE(csum_size, &csum_expected),
+			mirror_num);
 }
 
 #endif